ITP in the 21st century.

Immune (or idiopathic) thrombocytopenic purpura (ITP) is commonly encountered by the practicing hematologist. Clinical management decisions have traditionally been guided by individual training and past experience. Input from the literature has been more from observational reports of case series than from scientific results of hypothesis-driven research. Practice guidelines and several surveys of clinical hematology practice have highlighted important questions in the field, and in the past 5 to 10 years both clinical and laboratory investigations have produced valuable new information. Thrombopoietin levels are normal or only slightly increased in ITP, and stimulation of thrombopoiesis appears to be a promising new therapeutic approach in clinical trials. Chronic, refractory ITP in children or adults remains a challenge for the hematologist. It is this group that has the greatest risk of serious bleeding, particularly among the elderly. The anti-B-cell monoclonal antibody, anti-CD20, has shown benefit in phase I/II clinical trials in patients who had failed a number of previous therapeutic modalities. The standard for clinical research into therapy for ITP has become evidence-based medicine, and more prospective, randomized clinical trials are being completed by multi-institutional study groups.